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<br />001602 <br /> <br />When the 7-year research plan was initiated, its ultimate goals were (I) to identify the physical, <br />chemi<<al, and biological factors that limit endangered and native fishes and (2) to provide options <br />for conserving and restoring the endangered fish community (Bureau et al. 1992). Specific <br />objectives included: <br /> <br />I. Collect detailed information on the relative abundance and distribution of fisheries <br />in the San Juan River Basin, with emphasis on areas downstream of Navajo Dam. <br /> <br />2. Characterize physical habitat for fisheries in the San Juan River and the relationship <br />between flow and physical habitat. <br /> <br />3. Determine the biological response offish populations to the reoperation of Navajo <br />Dam. <br /> <br />4. Determine habitat use and needs of the Colorado pikeminnow and razorback sucker <br />in the San Juan River. <br /> <br />5. Characterize water quality in the San Juan River and identify critical quality issues <br />that may affect recovery of endangered species. <br /> <br />6. Identify interactions between native and nonnative species. <br /> <br />7. Identify and test management options which could improve reproduction and <br />recruitment of target species. <br /> <br />As noted in the objectives, the 7-year research plan included investigation ofthe entire native fish <br />community, rather than just the two endangered fish species. The roundtail chub was also <br />identified as a target species. Although it was not listed as endangered, it was considered for listing <br />in several parts of the Colorado River Basin and was rare in the mainstem San Juan River and other <br />areas. In addition, the studies comprising the 7-year research plan were developed to examine the <br />entire San Juan River, from Navajo Dam to Lake Powell, and investigate all life history phases of <br />the fishes (larvae, young, juvenile, and adult). A major aspect ofthe 7-year research plan, and of <br />the SJRIP, was evaluation of the biological effects of reo per at ion of Navajo Dam to mimic a natural <br />hydrograph. Reoperation primarily involved releasing higher flows during spring runoff and lower <br />flows during the rest of the year. Many of the studies were designed to investigate the biological <br />and habitat changes that occurred with the more-natural flow pattern. In addition, adaptive <br />management was included as an important component of the 7 -year research plan. This meant that <br />as new needs for research or management become evident, additional studies or management <br />actions would be implemented, even though the initial plan may not have foreseen those needs. <br /> <br />To meet these objectives, a biological studies series was formulated, and sampling began in 1991. <br />Table 2.1 shows the various studies that were implemented on the San Juan River in response to <br />the 7-year research plan, as well as the 1987 to 1990 studies. Four core biological studies were <br /> <br />2-5 <br /> <br />Program Evaluation Report <br /> <br />September 2000 <br />